Re: WAL format and API changes (9.5)

On 04/03/2014 07:11 PM, Tom Lane wrote:
>
> More generally, I'm pretty sure that your proposal is already going to
> involve some small growth of WAL records compared to today,

Quite possible.

> but I think
> that's probably all right; the benefits seem significant.

Yep.

OTOH, once we store the relfilenode+block in a common format, we can 
then try to optimize that format more heavily. Just as an example, omit 
the tablespace oid in the RelFileNode, when it's the default tablespace 
(with a flag bit indicating we did that). Or use a variable-length 
endoding for the block number, on the assumption that smaller numbers 
are more common. Probably not be worth the extra complexity, but we can 
easily experiment with that kind of stuff once we have the 
infrastructure in place.

- Heikki